Tivoli Storage Manager includes the following components:
You can set up servers in a network to allow you to manage them centrally and to balance storage resources.
To use your storage resources efficiently, you can arrange server storage into a hierarchy. You can then define when data is migrated from faster, more expensive storage pools (disk, for example) to slower, less expensive storage pools (tape, for example). You can also store data on another TSM system See Administrator's Guide for details.
TSM lets users on workstations do the following tasks:
Administrators define policy in the following policy objects: policy domains, policy sets, management classes, and backup and archive copy groups.
The following figure shows how TSM stores client data.
Figure 14. How TSM Controls Backup, Archive, and Space Management
(1) A client backs up, archives, or migrates a file. The file is bound to either the default management class or a management class specified in the client's include-exclude list.
(2) If, according to the management class, the file is eligible for backup, archive, or space management, the client sends the file and file information to the server.
(3) The server checks the management class or copy group to determine where in server storage to store the file initially.
If enough space is not available in the initial storage pool, the server examines the next pool in the hierarchy and places the file there if space is available.
(4) The server stores the file in the appropriate storage pool and stores information about the file in the database.
When files in server storage are migrated from one pool to another, the server updates the file information in the database.
A file remains in server storage until it expires and expiration processing occurs. A file expires based on criteria set in TSM policy. For example, backup policy may specify that up to two backup versions of a file can be kept in server storage. If a third backup version of a file is created, the oldest version in server storage expires. Backup policy may also specify that if a file is deleted from a client file system, it expires after 60 days.
During expiration processing, TSM deletes from the database those files that have expired.